Explanation:

Major industrial belts in India are:

a. The Hooghly Belt: This industrial belt has many jute textiles, cotton textiles, chemicals, engineering, paper, leather industries etc. Kolkata is a major city in this belt. Nearness to the coal and iron ore mines of Jharkhand and Bihar, cheap labour, fresh water from the Hooghly River has made this an important industrial belt of the region.

b. The Mumbai Pune belt: In this belt are located cotton textile mills, oil refineries, chemical and fertiliser industries etc. Development of hydro electricity in the Sahayadris and the availability of cheap labour from Gujarat and Maharashtra have made this an important industrial belt. Further, the port of Mumbai facilitates the transport facilities in and out of the region.

c. The Ahmadabad Vadodara Region: Ahmadabad has emerged as a major center of cotton textile industries. This region has many industries like chemical and fertilisers, plastics and engineering goods and services etc. Availability of skilled and unskilled labour has made it an important industrial region.

d. The Chennai Coimbatore Bengaluru Region: Cheap and skilled labour, availability of cotton and large markets has made this region an important industrial belt. Chennai, Coimbatore and Madurai are important centers of the belt.

e. The Chotanagpur Plateau Region: This region covers a part of West Bengal and Jharkhand. This region is rich in minerals like iron ore, coal , manganese, bauxite, mica etc. Jamshedpur, Bokaro, Durgapur are some important centers of steel production. Asansol, Ranchi and Dhanbad are some important centers of metallurgy and heavy industries. Due to the presence of rich deposits in this region, many industries are located here.

f. The Mathura Delhi Saharanpur Ambala Region: Two separate belts- between Faridabad and Ambala in Haryana and Mathura and Saharanpur in Uttar Pradesh merge in and around Delhi. The region has cotton textile, glass industry, chemicals and fertilisers, sugar and engineering industries. Cheap availability of raw materials, good transportation system and large markets has led to the establishment of many industries in the region.